Mechanical linkage

ABSTRACT

An arm connected to a push rod for moving a work load. The upper end of the arm is operably in contact with a movable fulcrum which is free to move downward whereby on its downward movement, the effort to move the work load is progressively reduced as the fulcrum moves downward.

United States Patent [1 1 [111 3,788,161 Krusemark Jan. 29, 1974 [54] MECHANICAL LINKAGE 3,039,322 6/1962 Ponrie .1 74/516 [76] Inventor: Frederick A. Krusemark, 303 3,693,472 9/1972 Hlrst, Jr. et al 74/518 Second Ave., Maywood, 111. 60153 [22] Filed: Feb. 24, 1972 Primary ExaminerBenjamin W. Wyche pp NO: 0 Assistant Examiner-F. D. Shoemaker Related U.S. Application Data [63] Continuation-impart of Ser. No. 86,080, Nov. 2,

1970, abandoned, which is a continuation-in-part of [57] ABSTRACT Ser. No. 524,115, Feb. 1,1966, Pat. No. 3,410,152

An arm connected to a push rod for moving a work [52] U.S. Cl ..l 74/516, 74/518, 74/561 load. The upper end of the arm is operably in contact [51] Int. Cl G05g 1/14 with a movable fulcrum which is free to move down- [58] Field of Search 74/516, 517, 518, 561 ward whereby on its downward movement, the effort to move the work load is progressively reduced as the [56] References Cited fulcrum moves downward.

UNITED STATES PATENTS 2,1 12,607 3/1938 Pooley 74/516 20 Claims, 10 Drawing Figures PATENTEDJAH 29 @914 3,788,161

SHEET 1 0F 4 Z34 ZJ MECHANICAL LINKAGE RELATION TO OTHER APPLICATIONS This application is a continuation-in-part application of my copending application Ser. No. 86,080, filed Nov. 2, 1970, now abandoned which in turn is a continuation-in-part of application Ser. No. 524,115, filed Feb. l, 1966, now U.S. Pat. No. 3,410,152 issued Nov. 12, 1968.

BACKGROUND OF THE INVENTION The invention of my earlier patent entitled ME- CHANICAL LINKAGE, Ser. No. 524,115, filed Feb. 1, 1966, now U.S. Pat. No. 3,410,152, issued Nov. 12, I968, comprises an arm'having a downward extension at one end which is pivotally mounted on framework; the other end of which carries a fulcrum roller. Another component, which completes the heart of the invention, is operably associated with the downward extension and one of several components that move forwardly when the pedal is moved forward. This invention contemplates an improved form of these components.

BRIEF SUMMARY OF THE INVENTION The present invention has the same basic embodiment covered in my issued U.S. Pat. No. 3,410,152, and includes a secondary fulcrum which becomes effective when fading occurs in a braking system. Also included are modified forms of the means that controls the movement of the fulcrum. In the drawings:

FIG. 1 is a side elevation view of the present mechanical linkage in a static position;

FIG. 2 is the same as FIG. 1 showing a change in position of the components when the pedal is moved forward;

FIG. 3 is a view taken on line 33, FIG. 1, in the direction shown;

FIG. 4 is an enlarged view taken on line 44, FIG. 1, in the direction shown;

FIG. 5 is a side elevation view as in FIG. 1, showing a different position'of theoperating rod means which is connected to a fulcrum rod;

FIG. 6 isthe same view as in FIG. 5, showing a different position and enlargement of the operating rod means, including anaddition, namely, a modified secondary fulcrum;

FIG..7 is a side elevational view partially in section of a modified form of the invention and downward in a first position;

FIG. 8 is a fragmentary view of a portion of the apparatus of FIG. 7;

FIG. 9 is a side elevational view of the apparatus of FIG. 7 showing the components of the apparatus in a position of operation; and

FIG. 10 is a side elevational view partially in section showing a modified form of the apparatus of FIG. 9.

Referring to FIG. 1, a bracket 10 is shown connected to a firewall 11. A depending arm means 12 is pivotally connected at its upper and lower ends .to the bracket 10 and to the pedal arm 13, respectively, thereby providing support means for the pedal arm 13.

A push rod.l4 engaging a master cylinder 15 is pivotally connected to pedal arm 13. A fulcrum arm 16 having a depending extension 17, is pivotally mounted on the bracket 10 and carries a rolling fulcrum 18 at the opposite end, that engages the upper end of the pedal arm 13, which, pedal arm 13 preferably, has a radius of a geometry such that the movement of the rolling fulcrum 18 will provide the optimum results.

An operating rod means 19 comprises a shaft 20 which is pivotally connected to the push rod 14, and has a bore 21 therein, which is provided with a slot 22. A shaft rod 23 having a drill hole 24 therethrough, is pivotally mounted on the depending extension 17 and is slidably mounted in the bore 21, which carries a spring 25 that is held in position by a pin 26 extending through the slot 22 and the drill hole 24.

A secondary fulcrum 27 is a part of the bracket 10, serving as a pivot point so as to provide a large volume of hydraulic fluid in the event of brake fading.

FIG. 2 shows the position of the rolling fulcrum 18 in its final travel against a stop means 28. Also, in the event of fading, the pivot point'would be transferred to the upper end of the pedal arm 13, thereby providing a large volumetric supply of hydraulic fluid.

FIG. 5 shows the shaft 20 pivotally connected to a secondary depending arm means 12a, and FIG. 6 shows a secondary shaft 20a provided with an extension threaded shaft 20b, pivotally connected to the pedal arm 13. Manifestly, the operating rod means 19 may be pivotally connected in various positions on components that move forward when the pedal 13 is moved forward.

Also shown in FIG. 6 is a modified secondary fulcrum means 27a comprising a fulcrum arm 29 extending through the bracket 10 by means of an aperture 30 and is pivotally mounted on the inner face 31 at the upper end of the pedal arm 13. The end of the fulcrum arm 29 that extends through the aperture 30 is provided with a modified secondary fulcrum stop means 32, which, preferably, is a threaded nut screwed on threads on the fulcrum arm 29 which permits adjustment so that the desired space is provided between the face of the aperture 30 and the modified secondary fulcrum stop means 32.

In the operation of the brake, the rolling fulcrum 18 will come to a halt when it contacts stop means 28, which, under normal conditions, stops the car with reduced pedal effort as compared with the operation of the conventional pedal. However, in the event of fading, the modified secondary fulcrum stop means 32 will be in contact with the faceof the aperture 30 and, therefore, the modified secondary fulcrum 27a functions as pivot point whereby a larger supply of volumetric fluid is provided, which manifestly is the equivalent in results to the performance of the secondary fulcrum 27.

It would appear evident that the heart of the invention comprises the fulcrum arm 16 and the operating rod means 19, which controls the movement of the rolling fulcrum 18.

It is obvious that the operating rod means 19 may be pivotally interconnected to the depending extension 17 and to any one of the components that move forward when the pedal arm 13 moves forward. In operation, the rolling fulcrum 18 may remain static in its position during a period when the slack is taken up in the braking system, after which it will move to a predetermined pivot point which, for instance, is I inch above the pivot point of the push rod 14, whereby there is substantially half the pedal effort as compared to the conventional system in which the pivot point of'the pedal arm 13 is 2 inches above the pivot point of the push rod 14.

Also, the pedal travel will be no greater than the conventional system, but may be less, depending on the position of the rolling fulcrum 18 above the pivot point of 5 the push rod 14. For instance, if the rolling fulcrum 18 is three inches above the push rod 14 pivot point as compared with the conventional system in which the pivot point is 2 inches above the push rod 14 pivot point, the pedal arm 13 will have less movement initially than the movement of the conventional pedal when the rolling fulcrum 18 moves to its stop position, referred to above. The mean pivot point of the rolling fulcrum 18 would be substantially two inches, and hence, there would be less pedal travel and substantially half the pedal effort.

Referring now to FIG. 7, there is illustrated an alternative form of the invention. The mechanical linkage embodying the invention, generally designated 100, includes a support bracket 110 secured to ground, such as, for example, a firewall 111 of an automotive vehicle. In the illustrated embodiment a master cylinder 115 of an automotive braking system is secured to the firewall 111 in operative association with the mechanical linkage 100, however, it must be understood that the mechanical linkage is effective for activation of any apparatus in which it is desirable to achieve the mechanical advantages obtainable with the present invention.

A push rod 114 forming part of the mechanical linkage is slidably supported by bracket 110. It extends through an appropriately formed aperture in the tirewall lll into operative engagement with the master cylinder 115. The push rod 114 includes a guide bar 130 extending generally parallel of the push rod and slidably disposed within a guide aperture 131 formed within the bracket 110. The slidable inter-engagement between the guide bar 130 and guide aperture 131 supports the push rod 114 in relation to the bracket 110. This inter-relationship precludes any movement of the push rod in a lateral or circumferential sense and maintains the push rod in alignment for slidable movement along its longitudinal axis. The push rod of the illustrated embodiment further includes an operator arm 122. This arm extends generally perpendicularly of the push rod 114 adjacent its free end and defines a bore 121.

The free end of the push rod 114 is pivotally connected to an actuator arm 113. In the illustrated embodiment of the mechanical linkage the actuator arm is in the form of a brake pedal arm which includes a brake pedal at its lower end (not shown).

The actuator arm 113 is supported by the bracket 110 through the push rod 1 14 and support bar 130. The upper portion of the actuator arm 113 defines a fulcrum contact surface 132 which is generally linear and includes stops 128 at opposite ends of the surface.

A fulcrum support arm 116 is provided which is pivotally connected to the bracket 110 at one end and carries a fulcrum roller 118 at its opposite free end in operative engagement with the fulcrum contact surface 132 of the actuator arm 113. The inter-engagement defines a fulcrum point about which the applied forces react upon activation of the linkage through applied force at the lowermost end of the actuator arm 113.

The fulcrum support arm includes an integrally formed, depending lever 117 adjacent the pivotal connection of the arm 116 to the bracket 110.

An operating rod, generally designated 119, is interconnected between the depending lever 117 and the push rod 114. This operating rod translates longitudinal movement of the push rod into pivotal movement of the fulcrum support arm 1 16 about its pivotal connection to the bracket 1 10. This, in turn, causes movement of the fulcrum roller 118 along the fulcrum contact surface 132 to effect the advantages of the invention.

The operating rod 119 is a lost motion-type linkage. At a predetermined point-of operation, further movement of the push rod 114 does not result in further movement of the fulcrum support arm 116. The movement is absorbed within the operating rod 119.

As best seen in FIG. 8, the operating rod 119 includes a shaft 134 pivotally connected to the depending lever 117. The shaft is operatively associated with the operator arm 122 and is slidably disposed within the bore 121. Pins 126 are pressed into appropriately formed apertures adjacent opposite ends of the shaft 134. A washer 136 is disposed adjacent the pin 126 nearest the pivotal connection to the depending lever 119.

A compression coil spring 125 is disposed intermediate the washer 136 and the operator arm 121. The pin 126 associated with the washer 136 prevents movement of the washer arrangement from the operator arm 121 due to spring action and the pin 126 adjacent the free end of the shaft 134 prevents withdrawal of the shaft 134 from the bore 121.

Longitudinal movement of the push rod 114 under the influence of applied load at the pedal end of the actuator arm 113 is transferred to the shaft 134 of the operating rod 1 19 through the spring 125 and washer 136. This movement, in turn, causes pivotal movement of the fulcrum support arm 116 and consequent movement of the fulcrum roller 118 in accordance with the principles of the invention.

Contact of the fulcrum roller 118 with the stop 128 prevents further movement of the fulcrum support arm 116. However, under-certain conditions of operation, it is necessary or desirable to allow further movement of the actuator arm 113 and push rod 114. This continued movement causes compression of the spring 125 of the operating rod 119 and effective shortening of the rod. Thus, the operator arm 12] connected to the push rod 114 moves toward the depending lever 117 without effecting further pivotal movement of the fulcrum support arm 116. This condition of operation is illustrated in FIG. 9.

The fulcrum contact surface 132 of the mechanical linkage illustrated in FIGS. 7 to 9 is generally linear. The depending lever 117 is sized and the fulcrum support arm 116 is sized and positioned upon the bracket such that its pivotal movement effected through the operating rod 119 maintains part of contact of the fulcrum surface 132 and the fulcrum roller 118 at the longitudinal axis passing through the center of the roller 118 and the pivot point of the fulcrum arm 116. This optimizes the effectiveness of the operating arm in causing movement of the fulcrum to its lowermost position in response to applied load.

The relationship between the fulcrum roller 118 and the fulcrum support arm 116 in the unloaded condition, as in FIG. 7, is such that slack in the linkage is taken up on initial application of load to the actuator arm 113 without movement of the roller 118. Thereafter, further applied load effects movement of the fulcrum support arm and fulcrum through operation of the operating rod 119.

FIG. is illustrative of a slightly modified form of the apparatus of FIGS. 7 to 9. It includes essentially all of the elements of the previous embodiment but illustrates a modifiedarrangement of-the operating rod The operating rod 119 includes a shaft 134, pins 126, washer 136 and spring 125. However, the operator arm 122 of the embodiment of FIGS. 7 to 9 is replaced by tab 138. This tab is formed upon the actuator arm 113 and defines a bore 123 which slidably receives the shaft 134.

The shaft 134 operates in cooperation with the tab 138 through spring 125 in a manner similar to the previous embodiment to accomplish desired positioning of the fulcrum roller 118.

As can be appreciated, the operating rod may take any form which allows for lost motion upon engagement of the fulcrum roller 118 with the stop 128. The linkages shown are merely for purposes of illustrating the principles of the invention.

In addition, the operating rod may be connected to any part of the mechanical linkage which will cause movement in response to applied load so that the movement can be translated into positioning movement of the fulcrum roller 118.

The secondary fulcrum arrangement shown in FIGS. 1 or 6 may also be associated with the forms of linkage shown in FIGS. 7 to 10.

Various features of the invention have been particularly shown and described. However, it must be appreciated that various modifications may be made without departing from the scope of the invention.

What is claimed is:

1. A mechanical linkage comprising a. a bracket connected to ground;

b. a fulcrum support arm pivotally connected to said bracket at one end, said fulcrum support arm including a depending lever adjacent said pivotal connection;

c. a fulcrum roller connected to the opposite end of said fulcrum support arm;

d. an actuator arm defining a fulcrum contact surface in operative contact with said fulcrum roller;

e. a push rod pivotally connected to said actuator arm and slidably supported by said bracket for longitudinal movementto move a work load in response to application of load to said actuator arm and movement of said actuator arm in response thereto; and

f. an operating rod operatively'connected between said depending lever and one of said push rod and said actuator arm, said operating rod effecting movement of said fulcrum roller along said fulcrum contact surface in response to applied load, said rod further including means providing lost-motion between said depending lever and one of said push rod and said actuator arm upon predetermined positioning of said fulcrum roller.

2. A mechanical linkage as claimed in claim 1 wherein said operating rod is connected to said push rod.

3. A mechanical linkage as claimed in claim 1 wherein said operating rod is connected to said actuator arm.

4. A mechanical linkage as claimed in claim 1 wherein said operating rod includes a shaft, a bore defining means slidably receiving said shaft, and a spring operatively interposed-therebetween whereby movement of said bore defining means is transferred to said shaft through said spring, said spring allowing relative movement between said shaft and said bore defining means upon predetermined positioning of said fulcrum roller.

5. A mechanical linkage as claimed in claim 4 wherein said bore defining means comprises an operator arm secured to said push rod and said shaft is pivotally connected to said depending arm.

6. A mechanical linkage as claimed in claim 4 wherein said bore defining means comprises a tab formed on said actuator arm and said shaft is pivotally connected to said depending arm.

7. A mechanical linkage as claimed in claim 1 wherein said actuator arm fulcrum contact surface is generally linear and said fulcrum roller contacts said surface at a point generally upon the longitudinal axis of said fulcrum support arm passing through said pivotal connection thereof to said bracket and the center of said fulcrum roller.

8. A mechanical linkage comprising:

a. a bracket connected to ground; 7

b. a fulcrum arm with a depending extension pivotally connected at one end thereof to said bracket;

c. a fulcrum connected to the other end of said fulcrum arm;

d. a pedal arm which, at its upper end, is operably engageable with said fulcrum;

e. support means for said pedal arm;

f. a push rod pivotally connected to said pedal arm which serves to move a work load, and

g. an operating rod means pivotally inter-connected between said depending extension and said push rod.

9. A mechanical linkage according to claim 1, wherein the said operating rod is pivotally interconnected between said depending extension and said pedal arm.

10. A mechanical linkage according to claim 1, wherein the said fulcrum is a rolling fulcrum.

11. A mechanical linkage .according to claim 1, wherein the said operating rod means comprises:

a. a shaft rod pivotally connected to said depending extension;

b. a shaft having a bore therein slidably engaged with said shaft rod and pivotally connected to said push rod;

c. a slot which extends through said shaft;

d. a drill hole through said shaft rod which carries a pin slidable in said slot, ande. a spring mounted in said'bore which is in contact with the end of said shaft rod.

12. A mechanical linkage according to claim 11,

wherein the said shaft is pivotally connected to a pedal arm.

13. A mechanical linkage according to claim 11 wherein the said shaft is pivotally connected to a depending arm means.

14. A mechanical linkage according to claim 1 wherein the upper end of said pedal arm has an arcuate face.

15. A mechanical linkage as claimed in claim 8 wherein:

a. said support means for said pedal arm includes a support bar slidably received by said bracket; and

b. a stop means is provided to inhibit the movement of said rolling fulcrum beyond a predetermined point.

16. A mechanical linkage as claimed in claim 8 wherein a secondary fulcrum is provided and which is engageable with the upper end of said pedal arm at a predetermined point.

17. A mechanical linkage according to claim 16 wherein the said secondary fulcrum is a component of said bracket.

18. A mechanical linkage according to claim 17 wherein said secondary fulcrum comprises:

a. an arm pivotally connected to the inner face of the upper end of a pedal arm;

b. an aperture in said bracket for receiving said arm,

and

c. a stop means at the end of said arm.

19. A mechanical linkage as claimed in claim I wherein stop means are provided on said actuator arm along said fulcrum contact surface to determine the limit position of movement of said roller.

20. A mechanical linkage as claimed in claim 19 wherein said operating rod lost-motion means allows further movement of said actuator arm and push rod after contact of said roller with one of said stop means. 

1. A mechanical linkage comprising a. a bracket connected to ground; b. a fulcrum support arm pivotally connected to said bracket at one end, said fulcrum support arm including a depending lever adjacent said pivotal connection; c. a fulcrum roller connected to the opposite end of said fulcrum Support arm; d. an actuator arm defining a fulcrum contact surface in operative contact with said fulcrum roller; e. a push rod pivotally connected to said actuator arm and slidably supported by said bracket for longitudinal movement to move a work load in response to application of load to said actuator arm and movement of said actuator arm in response thereto; and f. an operating rod operatively connected between said depending lever and one of said push rod and said actuator arm, said operating rod effecting movement of said fulcrum roller along said fulcrum contact surface in response to applied load, said rod further including means providing lost-motion between said depending lever and one of said push rod and said actuator arm upon predetermined positioning of said fulcrum roller.
 2. A mechanical linkage as claimed in claim 1 wherein said operating rod is connected to said push rod.
 3. A mechanical linkage as claimed in claim 1 wherein said operating rod is connected to said actuator arm.
 4. A mechanical linkage as claimed in claim 1 wherein said operating rod includes a shaft, a bore defining means slidably receiving said shaft, and a spring operatively interposed therebetween whereby movement of said bore defining means is transferred to said shaft through said spring, said spring allowing relative movement between said shaft and said bore defining means upon predetermined positioning of said fulcrum roller.
 5. A mechanical linkage as claimed in claim 4 wherein said bore defining means comprises an operator arm secured to said push rod and said shaft is pivotally connected to said depending arm.
 6. A mechanical linkage as claimed in claim 4 wherein said bore defining means comprises a tab formed on said actuator arm and said shaft is pivotally connected to said depending arm.
 7. A mechanical linkage as claimed in claim 1 wherein said actuator arm fulcrum contact surface is generally linear and said fulcrum roller contacts said surface at a point generally upon the longitudinal axis of said fulcrum support arm passing through said pivotal connection thereof to said bracket and the center of said fulcrum roller.
 8. A mechanical linkage comprising: a. a bracket connected to ground; b. a fulcrum arm with a depending extension pivotally connected at one end thereof to said bracket; c. a fulcrum connected to the other end of said fulcrum arm; d. a pedal arm which, at its upper end, is operably engageable with said fulcrum; e. support means for said pedal arm; f. a push rod pivotally connected to said pedal arm which serves to move a work load, and g. an operating rod means pivotally inter-connected between said depending extension and said push rod.
 9. A mechanical linkage according to claim 1, wherein the said operating rod is pivotally interconnected between said depending extension and said pedal arm.
 10. A mechanical linkage according to claim 1, wherein the said fulcrum is a rolling fulcrum.
 11. A mechanical linkage according to claim 1, wherein the said operating rod means comprises: a. a shaft rod pivotally connected to said depending extension; b. a shaft having a bore therein slidably engaged with said shaft rod and pivotally connected to said push rod; c. a slot which extends through said shaft; d. a drill hole through said shaft rod which carries a pin slidable in said slot, and e. a spring mounted in said bore which is in contact with the end of said shaft rod.
 12. A mechanical linkage according to claim 11, wherein the said shaft is pivotally connected to a pedal arm.
 13. A mechanical linkage according to claim 11 wherein the said shaft is pivotally connected to a depending arm means.
 14. A mechanical linkage according to claim 1 wherein the upper end of said pedal arm has an arcuate face.
 15. A mechanical linkage as claimed in claim 8 wherein: a. said support means for said pedal arm includes a support bar slidably received by said brackeT; and b. a stop means is provided to inhibit the movement of said rolling fulcrum beyond a predetermined point.
 16. A mechanical linkage as claimed in claim 8 wherein a secondary fulcrum is provided and which is engageable with the upper end of said pedal arm at a predetermined point.
 17. A mechanical linkage according to claim 16 wherein the said secondary fulcrum is a component of said bracket.
 18. A mechanical linkage according to claim 17 wherein said secondary fulcrum comprises: a. an arm pivotally connected to the inner face of the upper end of a pedal arm; b. an aperture in said bracket for receiving said arm, and c. a stop means at the end of said arm.
 19. A mechanical linkage as claimed in claim 1 wherein stop means are provided on said actuator arm along said fulcrum contact surface to determine the limit position of movement of said roller.
 20. A mechanical linkage as claimed in claim 19 wherein said operating rod lost-motion means allows further movement of said actuator arm and push rod after contact of said roller with one of said stop means. 